Lucia Soria-Tobar, Laura Román-Valero, Álvaro Sebastián-Serrano, Paloma Aivar, Beatriz Álvarez-Castelao, Miguel Díaz-Hernández
{"title":"Blockade of brain alkaline phosphatase efficiently reduces amyloid-β plaque burden and associated cognitive impairment.","authors":"Lucia Soria-Tobar, Laura Román-Valero, Álvaro Sebastián-Serrano, Paloma Aivar, Beatriz Álvarez-Castelao, Miguel Díaz-Hernández","doi":"10.1186/s13195-024-01600-x","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Alzheimer's disease (AD) is the most prevalent neurodegenerative disease. Three new drugs for AD based on monoclonal antibodies against the amyloid-β peptide (Aβ) have recently been approved because they favor the reduction of the burden of senile plaque in the AD patient's brain. Nonetheless, both drugs have very limited applicability and benefits and show several side effects. These limitations invite us to find alternative strategies for treating patients with AD. Here, we explored whether tissue-nonspecific alkaline phosphatase (TNAP), an ectoenzyme upregulated in the brain of AD patients and whose inhibition has beneficial effects on tau-induced pathology, is also efficient in reducing senile plaque burden.</p><p><strong>Methods: </strong>To evaluate whether TNAP may reduce cerebral senile plaque loading and Aβ-related toxicity, we use both pharmacological and genetic approaches. We analyze postmortem samples from human AD patients, APP/PS1 mice (a mouse model that mimics amyloid pathology observed in AD patients) treated or not with TNAP inhibitors, and the newly generated transgenic mouse line, TNAP-deficient APP/PS1 mice.</p><p><strong>Results: </strong>For the first time, we describe that genetic or pharmacological blockade of TNAP effectively reduces senile plaque burden by promoting its clearance, which leads to amelioration of cognitive impairment caused by Aβ-induced toxicity. These beneficial effects of TNAP inhibition occur concomitantly with higher microglial recruitment toward the senile plaque and increased microglial phagocytic capacity of Aβ by a mechanism involving metalloprotease-depending osteopontin processing. In addition, we also found that TNAP blockade favors LRP1-mediated transport of Aβ through the BBB.</p><p><strong>Conclusions: </strong>Here, we have shown that TNAP inhibition effectively reduces brain senile plaque burden and associated behavioral defects. Furthermore, given that we had previously reported that TNAP blockade also ameliorates Tau-induced neurotoxicity and increases lifespan of P301S tauopathy mouse model, we can state that TNAP blockade may be a novel and efficient therapy for treating patients with AD.</p>","PeriodicalId":7516,"journal":{"name":"Alzheimer's Research & Therapy","volume":null,"pages":null},"PeriodicalIF":7.9000,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11494749/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Alzheimer's Research & Therapy","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1186/s13195-024-01600-x","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CLINICAL NEUROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Alzheimer's disease (AD) is the most prevalent neurodegenerative disease. Three new drugs for AD based on monoclonal antibodies against the amyloid-β peptide (Aβ) have recently been approved because they favor the reduction of the burden of senile plaque in the AD patient's brain. Nonetheless, both drugs have very limited applicability and benefits and show several side effects. These limitations invite us to find alternative strategies for treating patients with AD. Here, we explored whether tissue-nonspecific alkaline phosphatase (TNAP), an ectoenzyme upregulated in the brain of AD patients and whose inhibition has beneficial effects on tau-induced pathology, is also efficient in reducing senile plaque burden.
Methods: To evaluate whether TNAP may reduce cerebral senile plaque loading and Aβ-related toxicity, we use both pharmacological and genetic approaches. We analyze postmortem samples from human AD patients, APP/PS1 mice (a mouse model that mimics amyloid pathology observed in AD patients) treated or not with TNAP inhibitors, and the newly generated transgenic mouse line, TNAP-deficient APP/PS1 mice.
Results: For the first time, we describe that genetic or pharmacological blockade of TNAP effectively reduces senile plaque burden by promoting its clearance, which leads to amelioration of cognitive impairment caused by Aβ-induced toxicity. These beneficial effects of TNAP inhibition occur concomitantly with higher microglial recruitment toward the senile plaque and increased microglial phagocytic capacity of Aβ by a mechanism involving metalloprotease-depending osteopontin processing. In addition, we also found that TNAP blockade favors LRP1-mediated transport of Aβ through the BBB.
Conclusions: Here, we have shown that TNAP inhibition effectively reduces brain senile plaque burden and associated behavioral defects. Furthermore, given that we had previously reported that TNAP blockade also ameliorates Tau-induced neurotoxicity and increases lifespan of P301S tauopathy mouse model, we can state that TNAP blockade may be a novel and efficient therapy for treating patients with AD.
期刊介绍:
Alzheimer's Research & Therapy is an international peer-reviewed journal that focuses on translational research into Alzheimer's disease and other neurodegenerative diseases. It publishes open-access basic research, clinical trials, drug discovery and development studies, and epidemiologic studies. The journal also includes reviews, viewpoints, commentaries, debates, and reports. All articles published in Alzheimer's Research & Therapy are included in several reputable databases such as CAS, Current contents, DOAJ, Embase, Journal Citation Reports/Science Edition, MEDLINE, PubMed, PubMed Central, Science Citation Index Expanded (Web of Science) and Scopus.